Delivery system for a tooth whitener using a strip of material having low flexural stiffness

ABSTRACT

A delivery system for a tooth whitening substance includes a strip of material having a flexural stiffness less than about 50 grams/centimeter as measured on a Handle-O-Meter per ASTM test method D2923-95. The strip of material is readily conformable without permanent deformation to a shape of a tooth when the delivery system is placed thereagainst. The tooth whitening substance is applied to the strip of material such that when the delivery system is placed on a surface of the tooth, the substance contacts the surface providing an active onto the surface. The substance also provides adhesive attachment between the strip of material and the surface to hold the delivery system in place for a sufficient time to allow the active to act upon the surface. A method of delivery includes pre-coating the strip of material, having the wearer apply substance to the strip of material, or having the wearer apply the substance directly to the surface before applying a strip of material.

FIELD OF THE INVENTION

The present invention relates to a system for the delivery of a toothwhitening substance to a portion of a tooth, the entire exposed surfaceof a tooth, or a number of teeth, and more particularly to such deliverysystem wherein the substance is protected from erosion within the mouthfor a time sufficient to enable an active provided by the substance tocause noticeable tooth whitening. Even more particularly, the presentinvention relates to disposable delivery systems used outside a dentistoffice, wherein such delivery systems are inexpensive and unobtrusive soas to be wearable without interfering with normal social discourse.

BACKGROUND OF THE INVENTION

The most common implement for dental hygiene is the toothbrush. Themechanical action of the toothbrush bristles aids in the removal of foodparticles, plaque, and the like. The toothbrush is normally used with atoothpaste. Prior to about 1955, a typical toothpaste consisted of asurfactant and an abrasive material. These products were simply intendedto augment the mechanical action of the brushing.

In 1955, CREST® toothpaste with fluoride, a Trademark of The Procter &Gamble Company of Cincinnati, Ohio, was introduced and the toothbrushand fluoride toothpaste combination proved to be a suitable means todeliver a fluoride treatment to the teeth surfaces. Subsequently, otheractive ingredients, such as tartar control agents, have been added totoothpaste to provide further dental hygiene benefits. Consumers havealso turned their attention to the cosmetic aspects of dental care, suchas teeth straightening and whitening.

Given the success of delivering chemicals which provide therapeuticbenefits for oral care, it is reasonable to expect similar success inaccomplishing the cosmetic benefit via routine brushing. For example,products have been introduced which claim to whiten teeth. However, inspite of the claims, the combination of the low allowable strength ofthe orally used chemicals and the significant contact time necessary forwhitening to occur effectively prevents significant whitening via aregular program of brushing. As a consequence, people who are seriousabout whitening their teeth and who have been disappointed by theresults of whitening dentifrices, often resort to professional help forwhitening their teeth.

Professional teeth whitening programs provided by dentists generallyfall into two categories: an in-office bleaching procedure and anoutside-the-office bleaching procedure. The in-office procedure involvesseveral visits, each of which begins with the fabrication of a speciallyfitted rubber dam within the mouth to prevent the bleaching chemicals,typically hydrogen peroxide, from contacting the soft oral tissue. Theproduction of the rubber dam within the patient's mouth may be bothpainful and time consuming. However, the strength of the peroxide bleachmandates the use of the dam. The in-office procedure may also leave theteeth sensitive to heat and cold and is very expensive.

The outside-the-office bleaching program differs in that the patientapplies the bleaching agent to his or her own teeth using a lowerstrength chemical over an extended period of time, typically severalhours a day for several weeks. The outside-the-office program typicallyrequires an initial fitting in the dentist's office for an appliancewhich is specific to the particular patient. The appliance is a devicethat is fabricated to fit precisely onto the patient's teeth and is usedto deliver to the patient's teeth a bleaching product, such as a gelcontaining urea/hydrogen peroxide complex. The patient is responsiblefor measuring and applying the bleaching agent to the surfaces of theteeth using the appliance as the means for delivery and containment.

Because the appliance is reused, it must be sufficiently robust toendure repeat handling, cleaning, filing, installation, and wearing.Such appliances are relatively rigid in order to maintain fit duringrepeat use. As a result, the edge of an appliance is generally stiff,often causing gum irritation; and its substantial thickness is usuallyapparent to both the wearer and others. Typically, a patient uses thedevice in time periods when social contact can be avoided.

There are now non-professional programs available to persons interestedin whitening their teeth using commercial products available at drugstores. The commercial products provide a kit which includes a genericappliance and a container of bleaching gel. The obvious appeal is thelower cost of the program. A major disadvantage of this "one size fitsall" appliance is the greater void between the interior walls of theappliance and the teeth versus the professionally fitted appliance.Hence, in order to insure intimate contact of the bleaching gel and theteeth surfaces, more bleaching gel is required. Furthermore, the poorerfit means a greater loss of bleaching gel onto the gums, into the oralcavity, and eventually ingested. The commercial kits, like theoutside-the-office professionally administered program, require the userto clean and to reuse the appliance. Since generic appliances are notfitted to the individual user, they are even more bulky in the mouththan the fitted appliances and thus they restrict social discourse to agreater degree.

One attempt to remedy some of the problems of the commercial kits isdisclosed in U.S. Pat. No. 5,575,654, issued to Fontenot on Nov. 19,1996. Fontenot discloses a prepackaged moldable dental appliance,adapted to fit a wide range of variously sized dental arches, whichcontains a premeasured amount of medicinal or bleaching agent. In use,the dental appliance is removed from the packaging, aligned in aparallel fashion to the edges of the teeth and pushed over the teeth inthe direction of the periodontal tissue until it covers the teethsurfaces. The primary benefit of the device disclosed by Fontenot iselimination of the measuring and filling of the appliance and thedisposability after each use. However, it has been observed that thedevice frequently has the problems of bulk and compromised fit.

A second solution is disclosed in U.S. Pat. No. 5,310,563, issued toCurtis et al. on May 10, 1994. Curtis et al. disclose a putty-likematerial which is formed by pressing against the teeth. It is held inplace by mechanical engagement with undercut surfaces and by friction.The composition encapsulates the active. The active migrates from thecomposition to the gums and tooth surfaces rather than being directly incontact with them. Presumably, the required wearing time is increased,which may be a significant negative.

What is needed is a low cost commercial delivery system, which has acustomized fit for a minimal volume of a tooth whitening substance, andwhich is in conformable contact with the appropriate tooth surfaces forrapid delivery of an active in such substance. In addition a deliverysystem is needed which does not require extensive user placementmanipulation to be certain of good contact. Furthermore, what is neededis a non-bulky active containment means that will permit the wearer touse the system during social discourse without interfering with thewearer's speech or appearance. Also needed is a containment means thatwill protect the tooth whitening substance from erosion from contactwith inner mouth surfaces.

SUMMARY OF THE INVENTION

In practicing the present invention, a strip of material is applied bythe wearer to a portion of a tooth, to an entire tooth, or to a row ofadjacent teeth. The side of the material facing the tooth is eithercoated with a tooth whitening substance or the teeth are coated with thesubstance and the strip of material is placed over the substance. Ineither case, the substance is preferably in a highly viscous state, suchas a gel, such that it provides not only the active but also tackinessbetween the tooth surfaces and the strip of material to hold the stripof material in place. The conformable strip of material is preferably ofa size that individually fits the entire upper or lower rows of teethwhen positioned against the teeth. As a soft, conformable material, thestrip may come into contact with the wearer's gums without causingirritation. The strip of material readily conforms to the teeth bylightly pressing it thereagainst and/or by the wearer gently suckingthrough the gaps between teeth. The strip of material is easily removedby the wearer after use by peeling it off. Each successive treatmentuses a fresh strip of material.

By being a relatively thin coating, the tooth whitening substance is lowin volume compared to the substance contained by rigid trays fitted orunfitted. Therefore, substance is not wasted, and little of it isaccidentally ingested or otherwise available for irritation of oralcavity surfaces for which it is not intended. Preferably, the strip ofmaterial and substance are substantially transparent so as to be almostunnoticeable when worn. Thinness of the delivery system enables thehigher temperature of the inside of the wearer's mouth to conduct heatthrough the strip of material to the normally cooler teeth in order toaccelerate the rate of diffusion of the active material into the surfaceof the teeth.

In one aspect of the present invention, a delivery system for a toothwhitening substance includes a strip of material having a flexuralstiffness less than about 50 grams/centimeter as measured on aHandle-O-Meter, available from Thwing-Albert Instrument Co. ofPhiladelphia, Pa. The strip of material is readily conformable withoutpermanent deformation to a shape of a tooth when the delivery system isplaced thereagainst. The delivery system also includes the toothwhitening substance applied to the strip of material such that when thedelivery system is placed on a surface of the tooth the substancecontacts the surface providing an active onto the surface. The substancealso provides adhesive attachment between the strip of material and thesurface to hold the delivery system in place for a sufficient time toallow the active to act upon the surface.

Preferably, the substance is in the form of a gel, which is asubstantially uniform continuous coating on the strip of material. Thestrip of material may have shallow pockets on a substance-coated side ofthe strip of material, such that the shallow pockets have substancelocated therein. The strip of material is preferably a piece of lowdensity polyethylene film having a nominal film thickness of about 0.013mm, which is substantially flat and rectangular in shape with roundedcorners, and the strip of material including the substance appliedthereon has an overall thickness less than about 1 mm. The strip ofmaterial may have a length sufficient to cover a plurality of adjacentteeth while conforming to the curvature of the wearer's mouth and gapsbetween the adjacent teeth. Ideally, the strip of material and thesubstance are substantially unnoticeable by others when worn.

In another aspect of the present invention, a method of delivering antooth whitening substance to a surface of a tooth includes the step ofapplying the substance onto a conformable strip of material having aflexural stiffness less than about 50 grams/centimeter as measured on aHandle-O-Meter. Alternatively, this step could include applying thesubstance onto the surface of the tooth. Another step is applying theconformable strip of material to the surface without permanentdeformation of the strip of material. The substance provides an activeonto the surface and also provides adhesive attachment between the stripof material and the surface to hold the delivery system in place for asufficient time to allow the active to act upon the surface.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims which particularly pointout and distinctly claim the present invention, it is believed that thepresent invention will be better understood from the followingdescription of preferred embodiments, taken in conjunction with theaccompanying drawings, in which like reference numerals identifyidentical elements and wherein:

FIG. 1 is a perspective view of a substantially flat strip of materialhaving rounded corners;

FIG. 2 is a perspective view of an embodiment of the present invention,disclosing the flat strip of FIG. 1 coated with a tooth whiteningsubstance;

FIG. 3 is a cross-section view thereof, taken along section line 3--3 ofFIG. 2, disclosing the flat strip having a thickness less than that ofthe substance coated thereon;

FIG. 4 is a cross-section view showing an alternative embodiment of thepresent invention, showing shallow pockets in the strip of material,which act as reservoirs for additional substance coated on the strip;

FIG. 5 is a cross-section elevation view of a tooth and adjoining softtissue, disclosing the strip of the present invention conforming to andadhesively attached to the tooth by means of the substance locatedbetween the tooth and the strip of material;

FIG. 6 is a cross-section plan view thereof, showing adjacent teethhaving the strip of material of the present invention conforming theretoand adhesively attached to the teeth by means of a substance locatedbetween the teeth and the strip of material;

FIG. 7 is a cross-section elevation view, similar to FIG. 5, showing thestrip of material of the present invention conforming to both the teethand the adjoining soft tissue and adhesively attached to the teeth bymeans of the substance located between the teeth and the strip ofmaterial; and

FIG. 8 is a cross-section plan view, similar to FIG. 6, showing a stripof material of the present invention conforming to the teeth and theadjoining soft tissue and adhesively attached to the teeth by means ofthe substance located between the teeth and the strip of material.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and more particularly to FIGS. 1 and 2,there is shown a first preferred embodiment of the present invention,which is generally indicated as 10. Embodiment 10 represents a deliverysystem for a tooth whitening substance. Delivery system 10 has a stripof material 12, which is initially substantially flat with roundedcorners. Strip of material 12 may be a single layer of polymer, woven,non-woven, foil, paper, rubber, or a combination thereof, such as alaminate.

Applied or coated onto strip of material 12 is a tooth whiteningsubstance 14. Preferably, substance 14 is a homogeneous fluid, uniformlyand continuously coated onto strip of material 12, as shown in FIG. 3.However, substance 14 may alternatively be a laminate or separatedlayers of components, an amorphous mixture of components, separatestripes or spots or other patterns of different components, or acombination of these structures including a continuous coating of oralcare substance 14 along a longitudinal axis of a portion of strip ofmaterial 12.

Substance 14 preferably contains or is itself an active, such as acomposition, compound, or mixture capable of influencing or effecting adesired change in appearance and/or structure of the surface itcontacts. Example actives include: hydrogen peroxide, carbamideperoxide, sodium fluoride, sodium monofluorophosphate, pyrophosphate,chlorhexidine, polyphosphate, triclosan, and enzymes. Examples ofappearance and structural changes include, but are not necessarilylimited to: whitening, stain bleaching, stain removal, remineralizationto form fluorapatite, plaque removal, and tartar removal.

As an alternative embodiment, a strip of material 16 may have shallowpockets 18 formed therein. When substance 14 is coated on asubstance-coated side of strip of material 16, additional substance 14fills shallow pockets 18 to provide reservoirs of additional substance14, as shown in FIG. 4.

FIGS. 5 and 6 show a delivery system 24 of the present invention appliedto a surface of a tooth or adjacent teeth. In adjoining soft tissue 20is embedded a tooth 22. Tooth 22 is herein defined as a portion of atooth, an individual tooth, or a set of adjacent teeth. FIG. 6 shows aset of adjacent teeth, for example. Adjoining soft tissue is hereindefined as tissue surfaces surrounding the tooth structure including:marginal gingiva, gingival sulculus, inter dental gingiva, gingival gumstructure on lingual and buccal surfaces up to and includingmuco-ginival junction and the pallet.

In both FIGS. 5 and 6, delivery system 24 represents strip of material12 and substance 14, with substance 14 on the side of strip of material12 facing tooth 22. Substance 14 may be pre-applied to strip of material12, applied to strip of material 12 by the delivery system user, orapplied directly to tooth 22 and then covered by strip of material 12.In any of these cases, strip of material 12 has a thickness and flexuralstiffness which enable it to conform to the contoured surfaces of tooth22 and to adjoining soft tissue 20.

Strip of material 12 serves as a protective barrier for substance 14 tosubstantially prevent leaching and/or erosion of substance 14 from thesurface of tooth 22 by the wearer's lips, tongue, other soft tissue, andsaliva contacting the substance. In order for an active in toothwhitening substance 14 to act upon the surface of tooth 22 over anextended period of time, from several minutes to several hours, it isimportant to minimize such leaching and/or erosion. The term "act upon"is herein defined as bringing about a desired change. For example, ifthe substance is a peroxide, it bleaches color bodies inside the toothto bring about whitening.

Strip of material 12 is held in place on tooth 22 by adhesive attachmentprovided by substance 14. Strip of material 12 has a flexural stiffnessless than about 50 grams/centimeter as measured on a Handle-O-Meter,model #211-300, available from Thwing-Albert Instrument Co. ofPhiladelphia, Pa., as per test method ASTM D2923-95. This relatively lowstiffness enables strip of material 12 to drape over the contouredsurfaces of tooth 22 with very little force being exerted. That is,conformity to the curvature of the wearer's mouth and gaps betweenadjacent teeth is maintained because there is little residual forcewithin strip of material 12 to cause it to return to its substantiallyflat shape: The flexibility of the strip also enables strip of material12 to contact adjoining soft tissue 20 over an extended period of timewithout irritation. This is in contrast to rigid and semi-rigid trays,even when fitted to the teeth, which are known to irritate the wearer'sgums due to rubbing. Strips of material 12 having a flexural stiffnessabove this upper value are prone to loosen and become dislodged fromtheir desired placement position. Strip of material 12 does not requirepressure forming it against the tooth. It does not permanently deformlike some prior art systems which require pressure to force a materialto take the shape of the teeth, and which fit by permanent deformationrather than drape.

The viscosity and general tackiness of substance 14 cause strip ofmaterial 12 to be adhesively attached about tooth 22 without substantialslippage under the potential fiction of lips and tongue and other softtissue rubbing against strip of material 12 during mouth movementsassociated with talking, drinking, etc.

FIGS. 7 and 8 show a delivery system 26 of the present invention appliedto a surface of tooth 22 as well as to adjoining soft tissue 20.Delivery system 26 represents strip of material 12 and substance 14,with substance 14 on the side of strip of material 12 facing tooth 22.Although strip of material 26 may not be adhesively attached toadjoining soft tissue 20, it may be held in position by being adhesivelyattached to tooth 22.

In a particularly preferred embodiment of the present invention,substance 14 is a tooth whitening gel containing 30-85% glycerin orpolyethylene glycol, 10-22% urea/hydrogen peroxide complex, 0-12%carboxypolymethylene, 0-1% sodium hydroxide, 0-10% triethanolamine(TEA), 0-40% water, 0-1% flavor, 0-15% sodium citrate, and 0-5%ethylenediaminetetraacetic acid. The preferred gel has a viscositybetween 200 and 1,000,000 cps at low shear rates (less than one1/seconds). Even more preferably, a tooth whitener is a gel containing70% glycerin, 5% carboxypolymethylene, 10% carbamide peroxide, 15% wateradjusted to pH 6.5 with sodium hydroxide. Commercial tooth whiteners,such as Opalescence and Nu-Pro Gold are also operable with the deliverysystem of the present invention.

Strip of material 12 is preferably a 0.013 thick piece of high densitypolyethylene film. The film preferably has an array of shallow pockets,typically 0.4 mm across and 0.1 mm deep. Strip of material 12 has aflexural stiffness of about 0.6 grams/centimeter as measured on aHandle-O-Meter, model #211-300, available from Thwing-Albert InstrumentCo. of Philadelphia, Pa., as per test method ASTM D2923-95. This test isa method for measuring the rigidity of polyolefin film and sheeting. Itdetermines the resistance to flexure of a sample by using a strain gaugeaffixed to the end of a horizontal beam. The opposite end of the beampresses across a strip of the sample to force a portion of the stripinto a vertical groove in a horizontal platform upon which the samplerests. A microammeter, wired to the strain gauge is calibrated in gramsof deflection force. The rigidity of the sample is read directly fromthe microammeter and expressed as grams per centimeter of sample stripwidth.

Flexural stiffness is a material property that is a function of acombination of strip thickness, width, and material modulus ofelasticity. In contrast to the low stiffness (and therefore high drape)of preferred strip of material 12, a typical appliance provided by adentist for an out-of-office bleaching program has a nominal thicknessof about 0.6 mm and a flexural stiffness over 300 grams/centimeter, asmeasured on a Handle-O-Meter per the above ASTM test.

When shallow pockets are included in the strip of material andsubstances are applied to it in various thicknesses, the overallthickness of the delivery system is preferably less than about 1millimeter. Thickness of the layer of substance 14 is preferably about0.4 mm.

Preferably, the delivery system of the present invention is used byapplying a tooth whitener to a tooth continuously for 120 minutes a day,once a day, for about 7 to 14 days to achieve a whitening benefit of 1-4shade guide improvement as measured by VITA LUMINO® Vacuum FarbskalaShade Guides, a product of VITA Zahnfabrik, of BadSackingen, Germany.

When the wearer removes the strip of material from the tooth, there maybe a residue of substance remaining on the surface. Residual substancemay be easily removed by brushing or rinsing.

While particular embodiments of the present invention have beenillustrated and described, it will be obvious to those skilled in theart that various changes and modifications may be made without departingfrom the spirit and scope of the invention, and it is intended to coverin the appended claims all such modifications that are within the scopeof the invention.

What is claimed is:
 1. A delivery system for a tooth whiteningsubstance, wherein the delivery system is substantially transparent andis almost unnoticeable when worn, comprising:a. a strip of materialhaving a flexural stiffness less than about 50 grams/centimeter asmeasured on a Handle-O-Meter per ASTM test method D2923-95, said stripof material being readily conformable without permanent deformation to ashape of a tooth when said delivery system is places thereagainst; andb. a tooth whitening substance applied to said strip of material suchthat when said delivery system is placed on a front surface of saidtooth, said substance contacts said surface providing an active ontosaid surface, said substance also providing adhesive attachment betweensaid strip of material and said surface to hold said delivery system inplace for a sufficient time to allow said active to act upon saidsurface.
 2. The delivery system of claim 1 wherein said substance is agel.
 3. The delivery system of claim 1 wherein said substance is asubstantially uniform continuous coating on said strip of material. 4.The delivery system of claim 1 wherein said strip of material hasshallow pockets on a substance-coated side of said strip of material,said shallow pockets having said substance located therein.
 5. Thedelivery system of claim 1 wherein said strip of material is a piece ofhigh density polyethylene film having a nominal film thickness of about0.013 mm.
 6. The delivery system of claim 1 wherein said strip ofmaterial is substantially flat and rectangular in shape with roundedcomers, said strip of material including said substance applied thereonhaving an overall thickness less than about 1 mm.
 7. The delivery systemof claim 1 wherein said strip of material has a length sufficient tocover a plurality of adjacent teeth while conforming to the curvature ofthe wearer's mouth and gaps between said plurality of adjacent teeth. 8.A method of delivering a tooth whitening substance to a front surface ofa tooth, said method comprising the step of:a. applying said substanceonto a comfortable strip of material having a flexural stiffness lessthan about 50 grams/centimeter as measured on a Handle-O-Meter per ASTMtest method D2923-95; and b. applying said conformable strip of materialwith said substance thereon to said surface without permanentdeformation of said strip of material such that said substance contactssaid surface, said substance providing an active onto said surface, saidsubstance also providing adhesive attachment between said strip ofmaterial and said surface to hold said delivery system in place for asufficient time to allow said active to act upon said surface.
 9. Themethod of claim 8 wherein said substance is a gel.
 10. The method ofclaim 8 wherein said strip of material is a piece of high densitypolyethylene film having a nominal film thickness of about 0.013 mm. 11.The method of claim 8 wherein said strip of material is substantiallyflat and rectangular in shape with rounded corners, said strip ofmaterial including said substance applied thereon having an overallthickness less than about 1 mm.
 12. The method of claim 8 wherein saidstrip of material has a length sufficient to cover a plurality ofadjacent teeth while conforming to the curvature of the wearer's mouthand gaps between said plurality of adjacent teeth.
 13. The method ofclaim 8 wherein said strip of material and said substance aresubstantially unnoticeable by others when worn.
 14. A method ofdelivering a tooth whitening substance to a front surface of a tooth,said method comprising the steps of:a. applying said substance onto saidsurface of said tooth; b. applying a conformable strip of materialhaving a flexural stiffness less than about 50 grams/centimeter, asmeasured on a Handle-O-Meter per ASTM test method D2923-95, over saidsubstance on said surface permanent deformation of said strip ofmaterial, said substance providing an active onto said surface, saidsubstance also providing adhesive attachment between said strip ofmaterial and said surface to hold said delivery system in place for asufficient time to allow said active to act upon said surface.
 15. Themethod of claim 14 wherein said substance is a gel.
 16. The method ofclaim 14 wherein said strip of material is a piece of high densitypolyethylene film having a nominal film thickness of about 0.013 mm. 17.The method of claim 14 wherein said strip of material has a lengthsufficient to cover a plurality of adjacent teeth while conforming tothe curvature of the wearer's mouth and gaps between said plurality ofadjacent teeth.
 18. The method of claim 14 wherein said strip ofmaterial and said substance are substantially unnoticeable by otherswhen worn.
 19. A delivery system for a tooth whitening substance,wherein the delivery system is substantially transparent and is almostunnoticeable when worn, comprising:a. a strip of material having aflexural stiffness less than about 0.6 grams/centimeter as measured on aHandle-O-Meter per ASTM test method D2923-95, said strip of materialbeing readily conformable without permanent deformation to a shape of atooth when said delivery system is place thereagainst; and b. a toothwhitening substance applied to said strip of material such that whensaid delivery system is placed on a front surface of said tooth, saidsubstance contacts said surface providing an active onto said surface,said substance also providing adhesive attachment between said strip ofmaterial and said surface to hold said delivery system in place for asufficient time to allow said active to act upon said surface.
 20. Adelivery system for a tooth whitening substance comprising:a. a strip ofmaterial having a flexural stiffness less than about 50 grams/centimeteras measured on a Handle-O-Meter per ASTM test method D2923-95, saidstrip of material being readily conformable without permanentdeformation to a shape of a tooth when said delivery system is placedthereagainst and said strip of material containing an array of shallowpockets; and b. a tooth whitening substance applied to said strip ofmaterial such that when said delivery system is placed on a surface ofsaid tooth, said substance contacts said surface providing an activeonto said surface, said substance also providing adhesive attachmentbetween said strip of material and said surface to hold said deliverysystem in place for a sufficient time to allow said active to act uponsaid surface.
 21. A delivery system for a tooth whitening substancecomprising:a. a strip of material made of polyethylene; and b. a toothwhitening substance applied to said strip of material such that whensaid delivery system is placed on a surface of said tooth, saidsubstance contacts said surface providing an active onto said surface,said substance also providing adhesive attachment between said strip ofmaterial on a said surface to hold said delivery system in place for asufficient time to allow said active to act upon said surface.